CN1198546C - Excimer Laser Eye Surgery System - Google Patents

Abstract

A compact excimer laser system is provided that includes argon fluoride laser gas, electronics, and laser head all compactly arranged such that the patient's bed can rotate over all of these components. This allows the patient's bed to be rotated for easy egress of the patient without striking the head against an optical extension through which the excimer laser is fired onto the patient's eye. Further, an automated lamellar keratoplasty system is incorporated into the electronics and components of the laser system so that laser in situ keratomileusis can be easily performed.

Description

Excimer Laser Eye Surgery System

The present invention relates to laser systems for eye surgery, and in particular to a compact excimer laser eye surgery system particularly suitable for laser in situ application of refractive keratomileusis.

Since the invention of glasses, doctors and scientists have been working to improve human vision. From eyeglasses, to contact lenses, to radial keratectomy, doctors are always looking for more convenient, long-lasting solutions to vision defects.

The development of excimer lasers offers a rare opportunity for vision correction. Excimer lasers, especially the 193 nm argon fluoride excimer laser, remove tissue by an athermal "ablation" process in which the tissue's molecular bonds are completely broken. This enables precise amounts of tissue to be removed without heating the surrounding tissue - which would burn the tissue leaving a scar. Ablation using excimer lasers has been used in a variety of methods to completely reconstruct the surface of the eye. These techniques are described in the assignee's U.S. Patent Application Serial No. 08/338495, filed November 16, 1994, and Application Serial No. 08/324782, filed October 18, 1994, both filed at This serves as a reference.

These techniques were taken a step further with the development of laser applied in situ refractive keratoplasty (LASIK), in which the superficial layers of the eye are excised and removed using ablative techniques The underlying stromal tissue. The superficial layer is then repositioned and the epithelium regrows and holds the superficial layer in place. This technology has been granted US Patent (Patent No. 4840175) by Gholam Peyman, which is hereby incorporated by reference.

But these technologies all benefit from efficient and compact workstations. Usually these techniques should be performed in a surgical grade clean room. Such clean rooms tend to be expensive, so any reduction in the footprint of an excimer laser surgical system would be beneficial. In addition, integration of functionality and improvement of efficiency are strongly desired.

Thus, according to the invention, an excimer laser system is provided in a highly compact form, wherein the patient operating table constitutes a housing in which the gas cylinder of the excimer laser system and the electronics for driving and controlling the excimer laser system are placed , the gas cylinder is usually filled with argon fluoride gas. In addition, the patient operating table preferably can be rolled out of the way to allow easy access to these components for maintenance.

The laser head is next to the operating table, but its height is lower than the operating table. The operating table includes a bearing that allows the operating table to rotate above the laser head and away from the excimer laser optical extension through which the laser beam is directed onto the patient's eye. This keeps the patient from bumping their head when standing up. Furthermore, the operating table can be rotated 90°, enabling non-laser eye surgery to be performed with the same equipment in the same clean room.

Also in accordance with the present invention, an automated lamellar keratoplasty (ALK) system is incorporated into the laser system, providing computer and monitoring and connectivity to the microkeratome. Two foot switches are provided, one for advancing and retracting the microkeratome and one for activating the microkeratome vacuum. This integrated system provides an easy-to-use, controlled system for performing laser applied in situ refractive keratoplasty (LASIK).

In conjunction with the accompanying drawings, the present invention can be better understood with reference to the detailed description of the following preferred embodiments,

in:

Figure 1 is a perspective view of a laser system according to the present invention;

2A-C are top, side and front views of a laser system according to the present invention;

3A-D are top, front, rear and side views of a patient table enclosure and patient table according to the present invention;

Figures 4A-C are top, front and side views of the equipment packaged in the patient operating table chassis of Figures 3A-D;

5 is a front view of the internal components of the system of FIG. 1, further illustrating an automated lamellar keratoplasty (ALK) system included for performing LASIK.

Referring to Fig. 1, there is shown a laser system L according to the present invention. The laser system is preferably based on a 193nm argon fluoride excimer laser, but other lasers may also be used. The patient table enclosure 100 includes a patient table 102 disposed thereon. The doctor's working platform 104 located diagonally opposite the patient's operating table 102 includes a keyboard 106 and a control input 108 . A keyboard 106 and control input 108 provide input to a computer system that partially controls the laser system L. The computer system provides data to the display 110 . The control input 108 , keyboard 106 and display 110 are used together with the computer system to control the laser system L and excite the excimer laser beam through the optical path vertically through the doctor workstation chassis 112 and then horizontally through the optical extension 114 . The source of the laser beam is an excimer laser head in the head housing 118 . When the patient is lying on the patient operating table 102, the optical extension part 114 guides the excimer laser to the patient's eyes, and also provides an optical instrument 116 for the doctor to observe the operation before or during the operation.

Optical extension 114 also includes an eye-tracking camera system that uses, in part, an optical path through doctor's table chassis 112 . The eye-tracking camera system preferably employs a high-speed camera and dedicated electronics working in conjunction with a computer system to maintain the laser optics aligned with the target point on the patient's eye.

The patient table enclosure 100 also includes a footrest 117 for use by the physician during surgery. The footrest 117 also includes two foot switches 119 and 121 that control the vacuum and power of the microkeratome in the automated lamellar keratoplasty (ALK) system used in the LASIK procedure. This will be further explained below with reference to FIG. 5 .

In addition, the eye-tracking camera system preferably uses a Transputer ^TM board produced by INMOS Co., Ltd. for use with a Transputer Frame Grabber ^TM produced by Parsytech Corporation installed in the computer system.

Referring to Figures 2A-C, various views of the system of Figure 1 are shown. The top view of FIG. 2A illustrates how the optical extension 114 extends well above the front 124 of the patient operating table 102 . The physician then uses optics 116 to observe the procedure while it is being performed.

Also from this position, it can also be seen that adjacent to the patient operating table 102 is the laser head housing 118 . The laser head in the laser head housing 118 emits a laser beam, preferably a 193nm excimer laser. The laser beam is emitted parallel to the table top and is then reflected vertically upwards, through the doctor's table chassis 112 , and then out of the optical extension 114 . The laser beam is then reflected down to the patient's eye at center point 120 .

Referring to Figure 2B, another view of the workstation is shown. This view represents the final beam path 122 of the beam that is emitted from the optical extension 114 down toward the front 124 of the table 102 . It can also be seen that if the patient sits up, his or her head will hit the optical extension 114 . In FIG. 2B , it can be seen that laser head 118 does not extend above patient operating table 102 . This feature will be appreciated in conjunction with Figure 3A described below.

Referring to FIG. 2C , which is an end view, again showing the beam path 122 in which the excimer laser light will impinge on the front 124 of the operating table 102 . Additionally, it can be seen that the height of the work position platform 104 is set so that the physician can easily access the keyboard 106 and the patient's head in the front 124 of the patient operating table 102 . Figure 2C also shows the patient table adjustment platform 125 that is part of the patient table housing. Adjustment platform 125 provides motorized control of patient table 102 in the x, y and z axis directions via controller 108 .

Referring to Figure 3A, the patient table 102 is shown in its rotated position. Patient table 102 rotates on bearings 126 that securely connect patient table 102 and patient table housing 100 . The position of the patient table 102 is adjusted by motors and pulleys 140 that provide x, y and z axis control of the adjustment platform 125 . Additionally, the patient table 102 rotates above the laser head 118 . The patient table preferably rotates sufficiently so that the front portion 124 of the patient table 102 rotates out from under the optical extension 114 . This allows the patient to sit up without their head hitting the optical extension 114 . In addition, the patient table 102 is preferably rotated 90° so that a single clean room can be used for laser and non-laser eye surgery. In this position (not shown), the surgeon will operate on the patient's head located in the front 124 of the patient operating table 102 but rotated 90° away from the platform 104 of the surgeon's work position. In addition, preferably an electrical solenoid 127 electrically locks into a latch hole 128 in the patient table 102 to hold the patient table 102 in place during the procedure. By positioning the laser head 118 below the surface of the patient table 102 , the patient table 102 can rotate above the laser head 118 .

Three additional views of the patient table 102 and the patient table housing 100 are shown in Figures 3B, 3C and 3D. FIG. 3B is an end perspective view of the front portion 124 of the patient table 102 showing the patient table 102 resting on the rollers 129 and held in place by the detents 130 . In effect, the patient table enclosure 100 constitutes a cover enclosing the cylinder containing the argon fluoride gas required for the laser head, the cooling components and the electronics required for the entire system. This will be further explained below in connection with Figures 4A-C.

The patient table housing 100 rolls in direction 131 over these components and is then held in place with detents 130 prior to operation of the system.

FIG. 3C illustrates a left (as viewed by the patient) side view of the patient table enclosure 100 and the patient table 102 .

FIG. 3D illustrates an end view (as viewed by the patient) of the patient table 102 and the rear of the patient table cabinet 100 . As shown, an additional recess 132 is formed for accommodating a laser head as described below with reference to FIGS. 4A-C.

In the case of FIGS. 3A-D , it can be recognized that there is a void formed below the patient table chassis 100 . This void serves to encapsulate the materials necessary for the laser system L to function. By providing the patient table enclosure 100 as a cover for these components, the patient table 102 and the patient table enclosure 100 can be easily rolled away from these components, thereby facilitating access and servicing of these components. At the same time, since cleanroom workspace is a precious resource, the use of such enclosed spaces in surgical systems is an advantage. Thus, a smaller and more compact system has the added benefit of reducing the size of the required clean room.

See FIGS. 4A-C , which are block diagrams illustrating the arrangement of components under the patient table enclosure 100 . Referring to FIG. 4A , shown is a gas cylinder 200 , electronics 202 for powering the laser system L and providing the computer system, and an inner laser head 204 . The AC power supply assembly is disposed in the gap 203 on the left side of the electronic device 202 . Electronics 202 include computer systems, operating table power supplies, and other system electronics, such as transformers and interface circuits. The inner laser head 204 is enclosed by the laser head housing 118, which produces a laser beam, preferably a 193nm excimer laser beam from the left side of FIG. 4 to the right side. Laser head 204 preferably includes an integral 30K volt power supply. In addition, components under the patient table enclosure include various cooling components 206 .

Referring to the end view of FIG. 4B , it can be seen that the gas cylinder 200 is mounted on rollers 208 for easy replacement of the gas cylinder 200 after the patient table housing 100 is rolled away. It can also be seen that a portion of the electronics 202 surrounds the gas cylinder 200, making more efficient use of space. Laser head 204 is again shown in FIG. 4B , along with exit points 210 and 212 for providing excimer laser beams which are then reflected transversely through optical extension 114 which constitutes the final laser beam guiding section. The final laser beam directing portion then redirects the laser beam to the patient's eye. The final laser beam guiding section includes the optics necessary to adjust the position of the excimer laser beam onto the patient's eye. Additionally, an aiming laser collinearly aligned with the excimer laser is preferably provided in the optical extension 114 . This preferably consists of two scopes, one for each axis.

Referring to Figure 4C, there is shown a side perspective view of the internal components as in Figure 3C. Again the electronics 202 can be seen surrounding the cylinder 200 .

Referring to Figure 5, another view is shown. In this case, the ALK, automated lamellar keratoplasty system 300 is incorporated into the laser system L. The Automated Lamellar Keratoplasty System is a system designed to assist in the LASIK procedure, the Laser Applied In Place Refractive Keratoplasty procedure. The procedure requires a microkeratome, which preferably includes a vacuum port to provide suction for attachment to the eye, and a power port to provide high-speed oscillatory motion of the blades. According to the technique described in the previously incorporated U.S. Patent to Gholam Peyman, once a flap is removed from the patient's eye while the patient's head is lying on the operating table 124, the flap is pulled back and the underlying tissue be excised.

However, such a system requires monitoring and control, so it is preferable to provide two foot switches 119 and 121 for the ALK system 300 . These switches turn the microkeratome vacuum and power on and off. Vacuum and power for the ALK are provided integrally through the laser system L through two ports 306 and 308 . Preferably a nurse stands by the doctor and adds the microkeratome when needed. Ports 306 and 308 could of course be located elsewhere in laser system L, but their integral nature facilitates operation. In addition, the ALK system is connected with electronics for monitoring. For example, if the vacuum fails, the operator will want to stop the movement of the blades immediately, since the high speed blade movement is necessary to prevent sticking to the laminar sheet as it is being removed. In addition, the ALK system can be further integrated and controlled by the computer system in the electronic device 202 through computer access. The computer system is preferably incorporated into electronic device 202 and controls various systems including display 110 , control inputs 108 and keyboard 106 . The computer system preferably controls the eye tracking camera system, the aiming system, the laser head 204 and the firing of the laser head 204 . In addition, the computer system preferably includes a remote disk drive slot 312 for insertion of a pre-distributed laser as described in assignee's co-pending U.S. patent application (Application No. 08/656,855) "Distributed Laser Surgery System," filed concurrently with the present invention. Program the laser cannon model.

The computer system and automated lamellar keratoplasty system 300 may also be combined. The automated lamellar keratoplasty system 300 generally provides a vacuum level output signal, a microkeratome voltage and current input signal, and a control input. The computer system can display the microkeratome voltage and current, and the degree of vacuum, and when a failure occurs, an alarm message can be generated, or the power source in the automatic lamellar keratoplasty system and the power source in the automatic lamellar keratoplasty system can be disabled. vacuum source. Additionally, a computer system may be disposed between the automated lamellar keratoplasty system 300 and the foot switches 119 and 121 so that the computer system controls the automated lamellar keratoplasty system 300 itself in response to the foot switches 119 and 121 .

Furthermore, by using the keyboard 106, the operator in this case can set the dynamics in the automated lamellar keratoplasty system 300 using feedback displayed on the display 110 according to the program executed in the computer system of the electronic device 202. The power level of the source, and the vacuum level of the vacuum source in the automated lamellar keratoplasty system 300.

In view of the foregoing description and accompanying drawings, it can be appreciated that the system of the present invention provides a compact excimer surgery system with a patient-friendly, rotatable operating table suitable for non-excimer laser surgery. In addition, the combined ALK system guarantees the convenience of laser in situ application of refractive keratoplasty.

Finally, the components are arranged under the patient operating table cabinet and the patient operating table, and near the laser head, which reduces the space occupied by the system and thus makes more effective use of the clean room environment.

The above disclosure and description of the invention are illustrative of the invention, and without departing from the spirit of the invention, dimensions, shapes, materials, components, circuit elements, circuit connections and contacts, and illustrated circuits, structures and operations Details of the method may be varied in various ways.

Claims (8)

1. A laser eye surgery system comprising: A laser head that produces a laser beam suitable for removing tissue from the eye; Connected with the laser head, used to drive the power supply of the laser head; An aiming system that provides an optical path starting from the laser head and aligns the laser beam at the patient's eye along the optical path, the aiming system also includes: a final laser beam guiding portion extending horizontally above the patient in the surgical position, When the patient is in the surgical position, the last laser beam guiding part guides the laser beam to shoot vertically onto the patient's eyes; A patient operating table integrally connected with the laser head and rotatably arranged below the last laser beam guiding part, the patient operating table can be rotated from a first position to a second position, and in the first position, the patient A surgical position located below the last laser beam guiding part, while in a second position, the patient is removed from under the last laser beam guiding part so that the patient can sit up easily without causing him or She hit her head on the last laser beam guide. 2. The system of claim 1, wherein when the patient is in the surgical position under the last laser beam directing section, the patient's eyes are located about half a meter below the last laser beam directing section. 3. The system according to claim 1 or 2, wherein the operating table is rotatably movable by about 30° from below the last laser beam directing portion. 4. The system of claim 1 or 2, wherein the operating table is rotatable through 90° to a second operating position enabling non-laser surgery. 5. The system of claim 1, wherein the laser head is an excimer laser. 6. The system of claim 5, wherein the excimer laser is an argon fluoride laser providing a laser beam of about 193 nm. 7. The system of claim 1, further comprising a solenoid positioned between the table and the table base, the solenoid securing the table in place when the table is in the surgical position. 8. The system of claim 1, wherein the operating table is rotatable on a single bearing attached to the base of the operating table.

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